On 16 Jun2019, at 10:48, Stefan Bauer <cubew...@googlemail.com> wrote: > our users send/receive via o365.
That’s not what you said. You said "some of our users use o365 but would like to use our service for outgoing mails.” > the last mile o365->recipient should go through our service like > o365->postfix->recipient I do not believe any company, much less Microsoft, is going to sent emails from their users to other users through your mail server. -- The Earth is like a tiny grain of sand, only much, much heavier.
